The spread of flu among old people could be halted with the introduction of a child vaccination programme, research suggests.
According to the Health Protection Agency, an annual jab for children under five could help protect the whole population. However, the side-effects of the vaccination in children are not yet known, according to the Joint Committee on Vaccinations and Immunisation (JCVI).
As children have lower immunity and come into close contact with family and each other they are often prolific spreaders of the virus.
But in 2005, concerns over the unknown nature of a child's reaction to such a treatment led the JCVI to call for more study into the effects of vaccination before flu immunisation in children could be considered.
Dr George Kassianos, immunisation spokesperson for the Royal College of GPs, told the BBC that the college had been calling for the introduction of influenza vaccination in children for the past five or six years.
He said: "The children themselves fare very badly from influenza but they are also the source of infection for many adults."